A thesis submitted in fulfillment for the degree of doctor of Philosophy in Management from Witwatersrand Business School at the University of Witwatersrand, December 2016 / Mining is an activity that many African countries depend on, and Africa’s export-oriented mining and quarrying is driven primarily by the commodity hunger of the world’s largest economies. In developing countries commodity exports form the most significant portion of exports. Although economic benefits are present because of mining activities, due to the scale and destructive nature of these mining activities some negative impacts are felt on the environment in terms of deforestation, land degradation, toxic water, and loss of farm lands to make way for mining activities. Using Botswana and Zambia as cases due to their institutional differences, mineral production and variety of ore, the study was conducted to see how mining activities affect communities in 216 households. Using a case approach, three primary sources of data in the form of household surveys, focus group discussions and the key informant interviews were used to capture data needed to answer the main research questions. Empirical research revealed that the socio-economic impacts of mining are mining induced displacement and resettlement (MIDR), the environment, infrastructure and social amenities, health, and the social fabric. The quantitative findings from the Relative Importance Index (RII) indicated that infrastructure and social amenities was the most important factor affecting communities, other important factors were health, and employment. Qualitative results highlighted negative environmental impacts as a result of a lack of law enforcement in Zambia, a fragmented social fabric in both Botswana and Zambia, and an overall improvement in health facilities more so in Zambia than Botswana. In addition, Zambia had a presence of mafia activity in the form of Jerabos and Chondos whereas Botswana had no reported evidence of mafia like activities. Theoretically, the study provided a new dimension of analysis of socio-economic impact which included the macro and meso-level as a better method of assessment of mining impact in communities. Through the empirical findings, a theory was abstracted to position the law as a key determinant of the quality of institutions and not just as one of the listed factors that affect institutional quality. The findings showed that the law greatly influences state capacity to promote economic development. A major difference in mining law in Zambia and Botswana is government’s involvement in the implementation of the law. Botswana shows evidence of more government influence on mining operations than Zambia which reduces the incidence of rent seeking behavior in Botswana, and shows that Botswana has better institutional quality than Zambia. However, global legal practices show that both countries require legal reform to improve their institutional quality and mitigate negative mining impacts. Legal frameworks for robust environmental protection, community engagement, and compensation are needed in both Botswana, and Zambia. Institutional quality is based on the extent to which the law is understood by all stakeholders and implemented. / MT2017

African copper PLC’s flagship is the copper producing Mowana mine located 129 km from Francistown in the North-Eastern part of the Republic of Botswana. The processing operation at Mowana is a standard flotation plant designed to produce copper concentrates from oxide, supergene, and sulphide ores. The expected average output of 16.2 tons per hour of copper concentrates has never been attained since plant commissioning. The major bottleneck has been established to be located around the crushing circuit of the Mowana production chain. The major hypotheses of this research are that performance in a crushing plant is adversely influenced by moderate and discrete changes in the process. The ultimate objective is to develop a dynamic process simulator, administered in Simulink/MATLAB® background, for application in the design of a control model utilising two crusher variables and a self-tuning control algorithm. In this research work, a process model describing the dynamic operation of an Osborn 57S gyrasphere cone crusher is investigated. Modelling of the Mowana crushing circuit is carried out by combining the steady-state and dynamic components of the crushing equipment in the Simulink/Matlab® environment. Eccentric speed (ES) and closed-side setting (CSS) are amongst the important inputs to the models. The rest of the inputs (crusher power, crusher cavity level, federate, pulley diameters, liner wear measurement, number of teeth of the pinion and bevel gear) are extracted from the data collected across the Mowana mine crushing circuit. While it has been demonstrated that the crusher CSS is the most influential controllable parameter, it has also been demonstrated that crusher capacity and power can be used effectively to optimise the circuit. The use of crushing power and cavity level control is suitable for the crushing circuit since the crushers are running on a constant ES and the CSS is set and reset manually. The outcome of the study presents an insight into the optimization of the Mowana mine crushing circuit through the design of a self-tuning controller for the cone crusher and for prototyping, parameters of a PID controller were determined in the Simulink/MATLAB® environment. The simulation involved the optimisation of the control model as a function of the cavity level of and the power drawn by the cone crusher. A self-tuning control algorithm at PLC and SCADA level of control was then tested. This formed the simulations and training platform. The outcome of the simulations carried out in this research needs to be validated against the real Mowana crushing process control upgrade. This will then inform the modifications and recommended crusher motor resizing exercise to be implemented. / Electrical and Mining Engineering / M. Tech. (Engineering: Electrical)